The main source of nitrogen oxides, the most important ozone precursor, is traffic.
The main source of nitrogen oxides, the most important ozone precursor, is traffic. Shutterstock/Canetti

Headline: Source Attribution of Ozone Concentrations in Germany by Identifying the Contributions of Precursor Substances to Ozone Formation


Tropospheric ozone is a potent greenhouse gas that is harmful to human health in high concentrations. A comprehensive overview of the sources of ozone precursors is needed to reduce the adverse impacts of both acute and long-term ozone exposure. In this project, researchers apply a new method for attributing the sources of ozone precursors.

The method described by a team led by IASS scientist Tim Butler, "Tropospheric Ozone Attribution of Sources with Tagging" (TOAST), makes it possible to identify ozone sources with considerable precision by tracking precursor emissions of nitrogen oxides (NOx) and volatile organic compounds (VOCs) separately. In this project, the researchers develop a concept for the use of the TOAST method in two different chemical transport models. This will enable them to assess the suitability of the method with higher confidence and to reliably quantify the remaining uncertainty in source attribution.

This research aims to develop a comprehensive understanding of the formation of ground-level ozone in Germany based on the location of NOx and VOC emissions and their respective sectors of origin. The researchers are also calculating the effects of ozone precursor emissions on human health and vegetation. Based on the findings of this source attribution, they will develop sectoral recommendations for mitigation measures at the local, regional and national levels in Germany as well as at the European and intercontinental level.